After his breakthrough 10 years ago in Band of Brothers, Damian Lewis's finest
work has been for television, his latest role that of a US Marine held
captive for eight years

Damian Lewis opens our conversation with a sheepish mention of his ardent admirers. 'I've a set of fans who call themselves – you're not allowed to laugh – Damian Bunnies.' Their name seems to be a reference to those other copper-top characters, the Duracell Bunnies. They have been following him since his 2001 breakthrough in Steven Spielberg's acclaimed Second World War series Band of Brothers, 'and they're absolutely lovely. In the end, I realised they knew so much about me, I let two of them run a fan site.'

A decade on from Band of Brothers, Lewis, about to turn 41 and with a busy, successful and cleverly below-the-radar career on both sides of the Atlantic, explains his approach to work. 'You want to do something that feeds you and that is stimulating and challenging to you. It makes your time more interesting.' But such an approach makes for a professional progression with 'a slower burn. No question. No question,' he repeats. 'Associations are the quickest way forward in this business. Not what role you played but who you worked with – what company you keep.'

It has to be said that Lewis has done all right by forswearing the showier roles – for which a drama school contemporary of his, Ewan McGregor, plumped from day one. 'Ewan was in the year above me. He always said, "I don't want to be a theatre actor, I want to be a film star." He was really clear about it. But I was going, "What? Films? I don't know anything about films! How do you even know how to be a film star?" ' Lewis's head and heart lay with Britain's theatre tradition. 'I was still stuck in the 1930s, with Tyrone Guthrie and the Old Vic and Richardson and Gielgud and Olivier.'

On graduating from London's Guildhall in 1993, Lewis quickly enjoyed notable successes on stage, with the Royal Shakespeare Company in Hamlet on Broadway in 1995, and in a National Theatre production of Ibsen's Pillars of the Community. But following Band of Brothers, television has been the platform for his greatest work. Playing the emotionally cruel patriarch in the 2002 remake of The Forsyte Saga and in the American drama Life (he played a wrongly imprisoned detective in the show, which ran for two seasons from 2007), Lewis has excelled. And the past six months have seen his small-screen success scale new heights.

In Homeland, made by the American cable channel Showtime, Lewis plays Sergeant Nick Brodie, a Marine who disappeared while serving in Iraq eight years previously. Liberated by US forces and returned home to a country that had long thought him dead, Brodie is greeted as a hero – by his brothers in arms, by a government keen for a propaganda victory in the never-ending war on terrorism, and by his wife and two children.

But there are complications and suspicions. Brodie's wife, believing she was actually a widow, has begun a not-so-covert relationship with one of her husband's closest comrades. His military buddies wonder why the back-from-the-dead Marine – regimental motto: semper fidelis (always faithful) – won't wrap himself more tightly in the flag and play the patriotic let's-kill-us-some-terrorists card. And within the CIA, an experienced Middle East analyst, Carrie Mathison (Claire Danes), is convinced that, in his eight years in isolated captivity, Brodie has been 'turned' by his jailers. Homeland's intriguing central proposition is this: what if jihadists had allowed the PoW to be discovered and liberated so he could return to his homeland, and thereafter set in motion the greatest terrorist outrage committed on American soil since 9/11?

'I thought it was ambitious and controversial to suggest that an American Marine – who is as great a symbol, a defender of their belief systems and freedom, as anything else – might possibly betray his country,' Lewis says. At last month's Golden Globes, Homeland won Best Drama Series. Lewis, nominated in the Best Actor category, lost out to the former Frasier star Kelsey Grammer, but Danes was crowned Best Actress in a TV Drama.

Amplifying the intrigue are the fractured psychological states of Brodie and Mathison. The CIA agent is as damaged as she is brilliant, suffering from a career-blotting incident in Baghdad and a bipolar disorder she keeps hidden from her superiors. This dovetailing of the lead characters' emotional states increased his enthusiasm for the part. 'They both suffer from extreme trauma,' he says, adding that both are cut adrift, their behaviour compromised by their mental and emotional turmoil. 'And this recklessness is what brings them together.'

The American producers of Homeland, Howard Gordon (24) and Alex Gansa (Entourage), offered Lewis the role, without an audition, over the phone while he was in Manchester last December filming the child-trafficking TV drama Stolen. They had seen him in the title role of Keane (2004), a brilliant and cruelly neglected independent film about a man searching for his missing daughter. 'In Keane, Damian holds the frame for the first 45 minutes of the movie all on his own,' Gansa says. 'It was just such a bravura performance. It also was about a very disturbed and troubled person, which obviously Brodie is, so we thought he'd be perfect for the role.'

Homeland, full of psychological twists and turns, has enjoyed impressive ratings in the US since premiering shortly after last year's 10th anniversary of 9/11. This timing was a marketing stroke to which Lewis professes not to have been privy. 'And it was lost on me, how powerful that was. Clearly that wasn't accidental,' he says, 'but I had no idea that that's what was going to happen.'

The series was adapted from an Israeli show called Hatufim (Prisoners of War), and has even been singled out for praise by Barack Obama. The news that the President was a huge fan inspired an editorial in the New York Times. Headlined the pungent aroma of paranoia, the column was published around the time of December's season finale. Having spent much of last year in the US, filming the show and promoting it, Lewis agrees that Homeland taps into the zeitgeist in its portrayal of ongoing anxiety in the US about terrorist threats. Osama bin Laden may have been 'got' last May, but there's a feeling that the threat from al-Qaeda and associated groups has only splintered and scattered.

In TV terms, Lewis continues, 'the immediate response to 9/11 was the more muscular, testosterone-filled 24. Which was [all about] plot. And it was very clearly good and evil. And we feel a bit differently about the war on terror now. We've gone to war in the name of defending Western democracy and our freedoms, but a lot of us don't like the way in which those wars have been perpetrated, and we feel ambivalent about our governments as a result.

'So, what if a soldier starts to think for a minute independently of the machine?' Lewis says carefully, mindful of avoiding any potential spoilers. 'And what conclusions might he arrive at? Of course it's fiction. But it's not too far off a realistic what-if situation.'

We meet in early January, in the lounge of a photographic studio in Kentish Town, north London, within (hefty) walking distance of the home Lewis shares near Parliament Hill with his wife, the actress Helen McCrory, and their children, Gulliver, five, and Manon, four. We discuss Gully's budding enthusiasm for Arsenal, the nearest home team in north London. It's a vexing topic for Lewis, an ardent Liverpool fan. Growing up in well-to-do St John's Wood, his insurance broker father was notionally a 'Gooner' but – being more of a rugby fan – never took his son to Highbury to see them play. So instead in the late 1970s young Damian was bedazzled by Liverpool, 'the coolest team with the coolest players who were winning a lot. And,' he grins, 'I have been that shallow ever since.'

But with the family having already done a two-year stint in Los Angeles (when Lewis was filming Life), and as Homeland requires him to be in North Carolina for five months a year (season two starts filming in May), Lewis acknowledges that local football allegiances matter more to him now. 'Unless something changes, I imagine we'll be in north London for the best part of Gully's growing up. So you think, it'd be great if he supports his local team, be part of the community. Because that's lovely and I never had that. I went to boarding schools, and I went young – for my parents' generation that was accepted. I really felt I only became a Londoner when I went to drama school at the age of 18.'

He is fond of casually dropping the names of his drama school contemporaries. Ewan McGregor, Joseph Fiennes ('We would potter next door to see Ralph playing leads at the RSC'), and more long-term friends such as Dominic West, whom he knows from his Eton days. 'Dom was a couple of years ahead of me,' Lewis recalls. 'You're a young kid, you want to be an actor, and I saw him playing Hamlet, and I remember thinking, "Wow, he's f***ing sensational… in his funny little tights," ' he jokes in a slangy, sweary London accent that belies his stoutly upper-middle-class background and 10 years at boarding school. 'I mean, he's a 17-year-old doing Hamlet – how great could he have been, let's face it!' Lewis grins, affectionately ribbing his peer and his own youthful callowness. Then, more joshing: 'But, cor, I fell in love that day.'

Throughout his twenties Lewis worked steadily. But he was 30 before Band of Brothers brought him headline success. His vivid portrayal of the real-life hero Major Dick Winters in the Spielberg and Tom Hanks-produced HBO series still reverberates to this day, not only for the Damian Bunnies, but for the military families he regularly meets while filming in the US.

Lewis tells a story of shooting an episode of Homeland in a Presbyterian church. The minister's son was in the US Army, and had just returned to Afghanistan for a second tour, 'and he was struggling mentally with his time there'. He asked if Lewis might film a video message to send to his soldier son. 'He wrapped his arms around me, squeezed me tight, and we both looked at the camera and I just said, "Hello, what you're doing out there is extraordinary, thank you so much. And I hope you get home soon." And this father, his eyes were filled with tears. Band of Brothers,' he reflects, 'brings a sort of a terrifying responsibility, and it's also been very moving.'

It must be freighted with deep personal memories for Lewis, too. His mother was killed in a car crash in India in 2001. In the year of his breakout success, when he was suddenly thrust into the spotlight, he was also coping with crushing private anguish. 'Well, it was a lot to take in,' he says slowly. 'It was a transforming year or two, definitely.' Another pause. 'And it is a shame that my mum isn't around to see more of it. That's all. Because she was the proudest hen in the coop.'

Lewis met Helen McCrory a couple of years later, around the time the actors appeared in Five Gold Rings (2003) at London's Almeida Theatre. Michael Attenborough, who directed the play, remembers Lewis as a brilliant stage actor. 'When he walks on stage he has a kind of energy inside him. People give it fancy names like presence and charisma, but they're posh names for energy. Damian walks on and you know something is going to happen. There's something inside him that's combustible and energised.'

Attenborough also recalls the emotional intensity between his two leads. 'I could have warmed my hands on it!' he laughs. 'It was like directing a fire. They were playing two characters who shouldn't be falling in love with each other – he was falling in love with his brother's wife. And Damian and Helen were incredibly sexy together. I wouldn't want to suggest that the only time you get sexy performances from people is when they fancy each other, but I'm absolutely sure it did us no harm!'

I ask Lewis if he and his wife would like to act together again. 'Yeah, definitely. I have a pipe dream of maybe running one of the smaller theatres in town. So, yeah, there are lots of notions running around.' Rupert Wyatt (Rise of the Planet of the Apes) understands where such 'notions' come from. He directed Lewis in The Escapist (2008), and they have a production company, Picture Farm, which produced The Baker (2007), directed by Lewis's brother, Gareth. 'Damian approaches a role from all sorts of different angles,' Wyatt says. 'He's like a sponge, he takes everything in. He has a very good insight into both his character and his place within the story. And nine times out of 10 an actor like that normally turns out to be a very good director.'

Today at least, though, Lewis deflates such ambitions. 'You know what I'll end up doing probably? Just bringing up my kids! Which will get in the way of all that. I'm being glib but I'm not really – it takes a lot to get you out of the house I find now, once you have children. You've got to be committed to a project.'

For Lewis, that means season two of Homeland and, before that, a trip to Italy this month to film a new adaptation of Romeo and Juliet written by the Downton Abbey creator Julian Fellowes and starring Hailee Steinfeld (True Grit) as Juliet and Douglas Booth (Great Expectations) as Romeo. More importantly, it also means giving McCrory a chance to follow her career. 'There's an unwritten if not unspoken – bloody hell,' he smiles, 'much spoken about deal that if I was going to go and do Homeland for five months, then for the next seven months of the year, I'd be at home. And I will try to honour that.' Another grin. 'I'll fail of course.'

Talk of his domestic arrangements sparks another name-dropping anecdote. 'We bought Hugh Laurie's house, totally coincidentally – I've never met him,' he adds with laugh. 'It wasn't directly from him; he'd been there two owners previously.' At the time, Lewis was about to relocate to LA to film Life. Laurie was there filming the medical drama House, and well on his way to becoming the highest-paid actor on television. Lewis thought the 'serendipity' was too powerful to ignore. He would value the advice of a British actor who had blazed a trail in US TV so successfully. He asked his agent to investigate whether Laurie might be available to speak to him on the telephone. 'He called me up and I was sitting in my then new bedroom. I said, "Thank you for taking the call, Hugh – but firstly I have to get one thing out of the way: I'm sitting in your old bedroom. And some of the photography I've found in the back of the wardrobe, you should have taken with you, frankly…" '

No, he adds hastily, he's joking. 'And Hugh was really lovely. I asked him what it was like doing a [US TV series] and he was realistic about how hard it was, but how fantastic the quality of the work is if you end up on something good. So, really, based on my conversation with Hugh, I took Life, and went to LA. I've still never met him in the flesh.'

And now, five years on, Lewis finds himself once again doing the transatlantic commute, in a hit American cable show that combines the political intrigue of The West Wing with the pulse-quickening drama of 24. He admits that, 'it's hard being away. Anything over three weeks is hard when your kids are that small.' But if he's forced to endure familial separation for months on end, at least he's doing it for an award-winning, ratings-trumping quality drama. The money's nice, too. 'Yeah, as the Americans would say,' Lewis says, smiling and sliding into his impeccable Stateside accent, 'it's a high-class problem.'